Bomb Defusal
for Experts

How a round works §0

One player, the Defuser, holds the bomb. Everyone else is an Expert with this manual. The Defuser can’t see these rules and you can’t see the bomb, so describe, ask and listen.

1. A 3-2-1 countdown runs before the timer starts. Open your manual and get ready.
2. The Defuser turns the bomb and reads out what each module looks like.
3. Find the module’s section here, ask for any casing details you need, then give clear instructions.
4. The bomb is defused when every regular module’s light is green.

Strikes and the timer

A mistake is a strike. Each strike makes the timer run faster: ×1.25 after the first, ×1.5 after the second. Reach the strike limit or run out of time and the bomb goes off. Some rules change once the bomb has strikes, so keep count.

Tip: agree on words before you start. “Up” and “down” for switches, symbol names from this manual, and “now” for the gauge.

The casing §1

Many rules depend on details printed on the outside of the bomb. Ask the Defuser to turn it over.

• Serial tag: a white sticker on one side. 6 characters. The last one is always a digit.
• Power cells: a holder on one side with 0 to 4 cylinders. Count only cells that are present.
• Status lamps: on the top. Each lamp has a 3-letter label and is either lit or unlit.
• Ports: on the back. Possible types:HexCoaxRibbonOptic
• Strikes: shown on the Defuser’s screen. Keep your own count too.

Write it down

Needy modules §2

On Medium and Hard, the bomb also carries a needy module. Regular modules sit quietly until you solve them. A needy module wakes up on its own, demands an answer, then goes back to sleep. It is never “solved” and it does not count toward the defused total.

• Everyone gets an alert when a needy module wakes up. The Defuser sees its screen light up.
• You have a short time to answer before its countdown ends.
• A wrong answer or a timeout is a strike. It then sleeps and wakes again later.
• Someone should own the needy module while the Defuser works on other modules.

The only needy module is the Status Query (Standard · v0.2). Its rules are in the last section.

Rotary Lock §3

A round dial with eight symbols, a colored ring, and one symbol on a cap in the middle.

Symbol names

Steps

1. Ask for the ring color and the center symbol.
2. In the table for that ring color, find the center symbol’s row. It gives three symbols, in order.
3. If the top of the bomb has a lit lamp labeled MAG, use the three symbols in reverse order.
4. Then, if the bomb has 1 or more strikes, move the first symbol to the end (A, B, C becomes B, C, A). Check the strikes before each ENGAGE.
5. For each symbol, the Defuser turns the dial until that symbol is under the yellow pointer, then presses ENGAGE.

Switchboard §4

Nine toggle switches in a 3×3 grid, with one indicator light above each column.

1. Use this table to get each column’s switch positions from its indicator:

2. If the last digit of the serial number is odd, flip the bottom row in every column.
3. If the bomb has 3 or more power cells, flip the top row in every column.
4. If the bomb has 1 or more strikes, also flip the middle row in every column. Check the strikes before you pull COMMIT.
5. “Up” means the lever’s yellow tip points toward the top of the module. When all nine are set, pull COMMIT.

Pressure Gauge §5

A round gauge with a moving needle, a colored face, and a number in a white box.

1. Ask for the face color and the number in the white box.
2. Which column? Use column 1 if the number is odd, column 2 if it is even.
3. If the bomb has no power cells, always use column 1 instead.
4. The Defuser calls out the needle position. Tell them to press VENT while the needle is inside the range.

The scale runs from 0 (far left) to 100 (far right). The needle swings in waves, so count the rhythm together before you call “now”.

Cipher Tape §6

A green display with five scrambled letters above five letter rollers.

1. Count the ports on the back of the bomb. Add 1. This is the shift (1 to 4).
2. Move every letter on the tape back by the shift. Wrap around: A back 1 is Z.
3. The result is one of the valid words. If it isn't, recount the ports.
4. The Defuser taps the top half of a roller to go forward and the bottom half to go back, then presses SUBMIT.

Alphabet

Valid words

Soundalike Relay §7

A display showing one word above six buttons (two rows of three), each labeled with a word. Three stages.

Careful: the words sound alike. Read the display and the labels out loud exactly as spelled, and spell them out if there is any doubt.

1. Find the row below that contains the word on the display.
2. From that word, count 1 place to the right along the row. Wrap around: after the last word comes the first.
3. If the serial number contains a vowel, count to the left instead.
4. If the bomb has 1 or more strikes, count 2 places instead of 1.
5. Press the button that shows the word you land on. Do this for all three stages; each stage shows new words.

Soundalike rows

Echo Sequencer §8

A big colored display above four symbol buttons in a row, with stage lights. The same four symbols appear every stage, but their positions are shuffled each stage.

1. Ask for the display color and which stage light is on.
2. Find that stage and color below, and give the instruction.
3. Some instructions refer to earlier stages. Write down the position and the symbol the Defuser pressed in every stage.
4. Positions count from the left, 1 to 4.

Plunger Button §9

A big round plunger with a color and a printed word.

1. Ask for the plunger color and the printed word.
2. Go down the list below. Perform the FIRST rule that applies, and ignore the rest.
3. TAP: press and release quickly. HOLD: press and keep holding. A colored strip lights up while you hold.

The plunger colors are Red, Blue, Yellow, White, Black.

• A press shorter than 0.7 seconds counts as a TAP. A HOLD must last longer.
• The seconds digits are the two digits that show the seconds: 4:37 gives 3 and 7; under a minute, 07.3 gives 0 and 7.
• If the bomb has 1 or more strikes, release a Orange strip when any digit on the timer is a 6 instead.

When to release a held plunger

Read the strip color, then let go when the Defuser’s bomb timer matches. The digits are the ones shown on the timer display.

Leave a half second of slack: call “ready” a little early so the Defuser can let go in time.

Status Query §10

A needy module: a small screen with a 2-digit countdown and YES / NO buttons. Usually asleep.

1. When it wakes up, the Defuser reads out the prompt on its screen.
2. Find the prompt below. The rule says when the answer is YES. Otherwise the answer is NO.
3. The Defuser presses the answer before the countdown ends.

• The prompt stays up for 25 seconds (20 seconds on Hard).
• A wrong answer or running out of time is a strike. Rules about strikes use the count at the moment you answer.